OBJECTIVE: This study examined whether volumes can be accurately measured at the expiratory valve of a conventional ventilator using pressure support ventilation and positive end expiratory pressure with software compensation for circuit compliance available in the Servo iota ventilator. DESIGN AND SETTING: Comparison of two methods for measuring tidal volume in an animal laboratory. SUBJECTS: Twenty healthy, intubated, sedated, spontaneously breathing pigs. INTERVENTIONS: Volume was measured in ten neonatal-sized and ten pediatric-sized pigs ventilated with the Servo iota ventilator using pressure support ventilation and positive end expiratory pressure with and without circuit compliance compensation. We compared volume measured at the airway opening by pneumotachography to volume measured at the expiratory valve of a conventional ventilator. MEASUREMENTS AND RESULTS: The use of circuit compliance compensation significantly improved the agreement between the two volume methods in neonatal-sized piglets (concordance correlation coefficient: with circuit compliance compensation, 0.97; without, 0.87, p=0.002). In pediatric-sized pigs there was improvement in agreement between the two measurement methods due to circuit compliance compensation (concordance correlation coefficient with circuit compliance compensation, 0.97; without, 0.88, p=0.027). With circuit compliance compensation off there was positive bias: mean difference (bias) 2.97+/-0.12 in neonatal-sized and 3.75+/-0.38 in pediatric-sized pigs. CONCLUSIONS: Our results show that volume can be accurately measured at the expiratory valve of a conventional ventilator in neonatal- and pediatric-sized animals.
OBJECTIVE: This study examined whether volumes can be accurately measured at the expiratory valve of a conventional ventilator using pressure support ventilation and positive end expiratory pressure with software compensation for circuit compliance available in the Servo iota ventilator. DESIGN AND SETTING: Comparison of two methods for measuring tidal volume in an animal laboratory. SUBJECTS: Twenty healthy, intubated, sedated, spontaneously breathing pigs. INTERVENTIONS: Volume was measured in ten neonatal-sized and ten pediatric-sized pigs ventilated with the Servo iota ventilator using pressure support ventilation and positive end expiratory pressure with and without circuit compliance compensation. We compared volume measured at the airway opening by pneumotachography to volume measured at the expiratory valve of a conventional ventilator. MEASUREMENTS AND RESULTS: The use of circuit compliance compensation significantly improved the agreement between the two volume methods in neonatal-sized piglets (concordance correlation coefficient: with circuit compliance compensation, 0.97; without, 0.87, p=0.002). In pediatric-sized pigs there was improvement in agreement between the two measurement methods due to circuit compliance compensation (concordance correlation coefficient with circuit compliance compensation, 0.97; without, 0.88, p=0.027). With circuit compliance compensation off there was positive bias: mean difference (bias) 2.97+/-0.12 in neonatal-sized and 3.75+/-0.38 in pediatric-sized pigs. CONCLUSIONS: Our results show that volume can be accurately measured at the expiratory valve of a conventional ventilator in neonatal- and pediatric-sized animals.
Authors: M L Cannon; J Cornell; D S Tripp-Hamel; M A Gentile; C L Hubble; J N Meliones; I M Cheifetz Journal: Am J Respir Crit Care Med Date: 2000-12 Impact factor: 21.405
Authors: Peter Andrews; Elie Azoulay; Massimo Antonelli; Laurent Brochard; Christian Brun-Buisson; Geoffrey Dobb; Jean-Yves Fagon; Herwig Gerlach; Johan Groeneveld; Jordi Mancebo; Philipp Metnitz; Stefano Nava; Jerome Pugin; Michael Pinsky; Peter Radermacher; Christian Richard; Robert Tasker Journal: Intensive Care Med Date: 2006-02-18 Impact factor: 17.440